Yashica 24 -- convert to 120?

[Donald Qualls]

This is a question of curiosity, not practicality, for me -- I already have a good TLR and don't need another (though I was tempted for several minutes this morning by a Seagull IVb that had the 6x4.5 mask in it -- finally decided it was too much money for the overall quality and having to use a red window all the time).

During that period of looking at eBay, however, I noted a couple Yashica 24 cameras offered for relatively low prices. I understand why they won't fetch as much as a 124 or other Yashica TLR -- the 220 film is gone and won't be back; anyone who doesn't have a freezer full of the stuff can't effectively use this camera.

Of course, you could load 120 and just put up with having to wind and shoot a bunch of times to convince the camera it's actually the end of the roll (and potentially deal with focusing a hair closer than the ground glass indicates because of the thickness of the backing). Pressure plates aren't too hard to alter; you could probably correct something to get the film back into agreement with the ground glass.

The bigger issue is the film advance. I don't know if the 24 uses a turns counter or length counter, and if the former, there's the issue of constantly increasing frame spacing, such that frame 12 might fall off the film tail. If it's a length counter, of course, that's not a problem.

The real question is, either way, whether it's practical for someone willing to deep disassemble the advance and frame counter system to convert the counter to freewheel after frame 12 instead of after frame 24?

 

[Dan Daniel]

Sure, easy. The film metering (frame spacing) system is the same as other YashicaMats and such- the thin small toothed gear riding along the edge of the backing paper. If you remove the gear teeth that the metering gear uses after it gets to 12 on the metering disk, it will behave like a 120 camera. Or fill in the notches in the brass disk after 12 so the pawl never engages to stop the winding mechanism.

 

[Donald Qualls]

Sure, easy. The film metering (frame spacing) system is the same as other YashicaMats and such- the thin small toothed gear riding along the edge of the backing paper. If you remove the gear teeth that the metering gear uses after it gets to 12 on the metering disk, it will behave like a 120 camera. Or fill in the notches in the brass disk after 12 so the pawl never engages to stop the winding mechanism.

Okay, that makes sense. Length-counting is good (changes in film thickness won't cause mis-framing), and a few minutes with a soldering iron and a few more with a file or Dremel will fix up the counter cam. A couple hours' work, then, will convert a 24 into a 12. Good to know; if I come across a screaming deal on one, I might just grab it.

 

[Raghu Kuvempunagar]

the 220 film is gone and won't be back; anyone who doesn't have a freezer full of the stuff can't effectively use this camera.

It seems Shanghai GP3 ISO 400 film is currently being made available in 220 format. Saw some FB discussion on it.

 

[Donald Qualls]

It seems Shanghai GP3 ISO 400 film is currently being made available in 220 format. Saw some FB discussion on it.

I don't see any indication eBay knows about it, if that's true. If I were certain that was going to be the case, I'd be strongly inclined to buy a camera like a Yashica 24 or 124 (already got a 220 back for my RB67, which I bought to shoot 35mm pano). But unless I got wind of it ahead of the rest of the world, the price differential would evaporate and a 24 would wind up costing $300 like a 12 or 124 does now.

 

[Raghu Kuvempunagar]

@Donald Qualls:
Zhou Pierre is the guy who announced the availability of Shanghai GP3 in 220 format. He is also the guy who coordinates the annual custom size sheet film orders with the factory that makes Shanghai GP3 film. You need to place your order for 220 film through him if you're interested. Not sure if it's going to be available on eBay anytime soon.

 

[Donald Qualls]

Thanks for the tip, @Raghu Kuvempunagar . I don't think I'll worry about it. The question was because I've been seeing Yashica 24 (220-only cameras) for about half the price of other Yashica TLRs of similar vintage (Yashica 12, for instance). If I didn't already have a good TLR, it would be tempting to get one to convert (rather than hope for 220 film to return).

If the GP3 in 220 shows up in the general market as fresh emulsion at a reasonable price, I might grab a few rolls -- I recall that being good film -- but all I'd gain with equipment I have now is 20 shots on a roll with 6x7 instead of 10, with a camera I only use on a tripod (because an RB67 is heavy). Rolls being too short isn't a problem I usually have with that camera.

 

[grat]

I wonder if Mark Hama can convert a Yashica 24 to a Yashica 12?

 

[Donald Qualls]

I wonder if Mark Hama can convert a Yashica 24 to a Yashica 12?

From what was described above, the simplest way would be to replace the advance stop wheel with one from a 12; if those parts are available, it should be relatively easy. Good likelihood that the same part from other models would also fit -- first-gen Mat, for instance, C or D model (I don't recall when they switched from red window to crank and counter).

 

[Dan Daniel]

From what was described above, the simplest way would be to replace the advance stop wheel with one from a 12; if those parts are available, it should be relatively easy. Good likelihood that the same part from other models would also fit -- first-gen Mat, for instance, C or D model (I don't recall when they switched from red window to crank and counter).

Nope. They've modified both the disk and the gearing of the wind metering to have 24 frames in what used to be the 12 frame space (give or take). Instead of redoing the gearing, the diameter of the disk, etc., the way to do it is what I described- simply fill in the notches hat the pawl drops into for frames 13-24, and see how they stop the disk from continuing to rotate while winding off the film and duplicate that at the proper spot on the disk.

Getting into changing out gearing, figuring new ratios, etc.- just buy a 124 and save yourself the trouble and the odds of just wasting your time trying to build a 12 frame camera into a 24 frame system. I mean, if you like reinventing the wheel, go for it. But everything you need is in there, you just need to prevent a couple of things from happening after the 12th frame.

 

[Donald Qualls]

They've modified both the disk and the gearing of the wind metering to have 24 frames in what used to be the 12 frame space (give or take).

Makes sense. They'd only have built them with a drop-in wheel swap if the 12 was originally designed to become the 24.

I'd love to have a 124G, except I can get an M645 with a normal lens and prism finder for about $50 more, if I shop around a bit. I like TLRs, but I like SLRs and 645 even better.

 

[reddesert]

All of the Yashica-Mats with a crank use a sensing wheel that rides on the film on the takeup spool, so frame spacing will be correct. Some of the knob wind models also have auto stop.

There are a lot of old internet threads about using 120 film in the Yashica-24. Most of these seem to be concerned about the added thickness of film+paper jamming the advance (shouldn't be a problem) or the film location WRT rails/pressure plate (likely only a problem at wide open aperture). I don't really see the reason to modify it. The worst that would happen is that you need to wind off several more frames to wind up the backing paper.

The Mat-124G is sort of overpriced because it was the last model and the "default choice" for beginner medium format, so it has a lot of recommendations and is a bit of a fetish object, the same way that (IMO) the Pentax K1000 is overpriced now relative to other contemporary SLRs because it was the highly recommended default BITD. Condition matters more; given good condition, any of the Yashica-Mats should perform about equally well, especially if you use a separate meter.

 

[beemermark]

Not an answer but a question - couldn't you just continue to wind until the film is wound onto the take up spool? Generally in most 120 cameras you can tell by feel when the film is wound on. As far as film thickness just clue some 120 backing paper onto film pressure plate,

 

[Donald Qualls]

Not an answer but a question - couldn't you just continue to wind until the film is wound onto the take up spool? Generally in most 120 cameras you can tell by feel when the film is wound on. As far as film thickness just clue some 120 backing paper onto film pressure plate,

Sure you could, as long as the counter resets when you open the door or is otherwise easily restarted.

But putting backing paper on the pressure plate would be for using 220 in a 120 camera, in this case it's a 220 camera and you've already got one more layer of backing than it was designed to use.

It's tempting, if I had the money to spare right now I'd go ahead and pull the trigger. Much easier to load than my Reflex II (trimming the spool to fit the 620 spool chamber is a PITA).

 

[thuggins]

Why would the pressure plate be an issue? The film position is determined by the film gate. The pressure plate just holds the film against the film gate.

 

[Dan Daniel]

Why would the pressure plate be an issue? The film position is determined by the film gate. The pressure plate just holds the film against the film gate.

Actually, no. The pressure plate creates a channel for the film to move within. It does not actually press the film flat to the film gate. There is a small amount of free play in any film channel. I seem to remember numbers of .002-.005 inch some times ago?

A 220 pressure plate sits tighter because there is not backing paper. So running 120 film could, theoretically, have the film be pressed against surfaces such as the entry and exit points and cause scratching. Also excess winding force needed to overcome friction. And maybe, the film could 'pop' forward into the opening under pressure.

Theoretically. Seems people run 120 film through 220 systems all the time without problems. Ideally, yes, you would raise the pressure plate and create slightly deeper channel for the film to travel. this is what happened when you move a pressure plate from the 220 to 120 position. Thin tape or such material on the edges where it rests to determine the channel opening is the place to modify to move from 220 to 120.

 

[itsdoable]

From the manual:

 

[Donald Qualls]

Well, that just about covers that, then. Looks like a 24 is a viable alternative to the more expensive Yashica TLRs, especially if I can spot one with a Yashinon.

 

[cayenne]

I'd seen that FB link to 220 film from a link form a YouTube show Nico's Photography Show.

https://www.facebook.com/pierre506/posts/10215891422192313

If 220 film came back, I was thinking of picking up maybe a good condition used Hasselblad 220 back while still cheap.....to play with this.

C

 

[Zathras]

Well, that just about covers that, then. Looks like a 24 is a viable alternative to the more expensive Yashica TLRs, especially if I can spot one with a Yashinon.

Hi Donald, I'm pretty sure that all the 24s came with the Yashinon. It also has the ƒ2.8 viewing lens, which does make it a little bit easier to focus.

 

[Deleted member 88956]

It's funny how this thread went from "well informed" inner knowledge of Yashica's mechanical design to Yashica's own manual shuttering that with few simple words.

 

[Deleted member 88956]

Pressure plate holds film against film gate runners. Using 120 film in 220 set up may show scratch marks along film's length (frame's side edges, not across) as the pressure applied is somewhat higher due to additional backing paper in the path. This however will directly depend on how film gate runners were finished off in production (or later in "repair"). Well machined cameras are unlikely to cause this problem. Pressure pate function is easier to see in some 35 mm cameras (Altix n comes to mind) where pressure plate is actually loosely hinged on film gate section, then spring pressed into position upon back closing.

All the 120 in 220 talk and worries is about motorized backs and fear of burning the motor due to somewhat higher friction, most of which is unsubstantiated and mostly only theoretically true. I don't know of one film insert that does not allow a simple part flip to fool it as being one or the other counter wise (at least in Mamiya 645 or Pentax 645 are so). Never looked at interchangeable film holders so am not sure if same is true.

 

[Donald Qualls]

I don't know of one film insert that does not allow a simple part flip to fool it as being one or the other counter wise (at least in Mamiya 645 or Pentax 645 are so). Never looked at interchangeable film holders so am not sure if same is true.

As far as I've been able to find out, the Graflex and Mamiya roll holders -- at least on the 2x3 Graflok mount -- are hard-geared for the chosen roll type, either 120 (can't be made to count past 10, 12, or 16 frames) or 220 (can't be made to freewheel after 10 frames in 6x7). Which is fine, for my applications.

 

[Dan Daniel]

By the way, Donald, the Rolleicord Va or Vb with the 6x4 adapter kit is a very nice 6x4.5 setup. They also made it for the T, but the internal film gate mask is different and not interchangeable with the Rolleicord internal film gate mask. For the Rolleicord, be certain that the frame counter dial with '16' marked on the surface is included. For all of them, there should be the internal mask, and masks for the ground glass and the sports finder for both 6x4 and 4x4 superslides.

I would focus normally and use the sports finder for framing portrait mode shots. Obviously not the fastest way to work. A prism would solve this but creates new issues.

 

[Donald Qualls]

@Dan Daniel I've now got a Mamiya 6 folder (6x6/6x4.5), Daiichi Zenobia (6x4.5 scale focus folder), 6x4.5 roll film holder for my RB67, 6x4.5 masks for my Wirgin Auta 4.5 -- the only 6x4.5 I'd add at this time is if I fell into enough money to get a Mamiya M645 kit with a prism and 2-3 lenses. Shooting a TLR in a format that requires turning it on its side might possibly be over the line where it stops being fun...